Catatonk Island is supposed to be 20 miles off-shore. This can not be true. There is a scene from the island that shows the mainland in the distance across the ocean. Mohegan Island, where the film was actually shot, is 12 nautical miles (22 km) off-shore, just within the critical distance for being able to see "over" the horizon when viewed from the elevated cliffs. If the island was truly 20 miles off-shore one would not see the mainland just ocean.